Worcester Boiler change to Combi

[Robsparky99]

Hi All,

I'm looking into changing my conventional boiler (Worcester 30CDi conventional) to a Worcester Greenstar 8000 Style 30kW Combi.
My house has 2 bathrooms/4 beds - showers (Aqualisa) in both bathrooms, but never likely to be on at the same time.

Has anyone made the switch with these boilers? Is 30kW version ok?

I have 22mm gas pipework with this recent service info, but being told that I need 28mm for 35kW or above:
Analyser readings App 1
Working pressure (at meter) 21.9mb mbar
Working appliance pressure 18.2mb mbar
Co parts per million 6ppm low / 34ppm high
Percentage co2 8.7% low / 8.7% high
Percentage oxygen NA
Co/Co2 ratio 0.0000 low / 0.0004 high
Gross flue gas temperature NA
Gas rate (if applicable) 29.6kw

 

[Timmy D]

Looking at those working gas pressures and the M.I’s stated drop across the gas valve, you’re gonna struggle to put a 30kw in on the current pipework.